In a large-scale integration (LSI) manufacturing process, a transistor structure includes a gate stack structure configured to control a limit voltage of a transistor, in which a high-k dielectric film having a dielectric constant of more than 4 is formed on silicon and a conductive thin film is formed on the high-k dielectric film. In the transistor structure, various conductive thin films are used as a gate electrode to control power consumption of the transistor. These conductive thin films include specific work functions (WF). The threshold voltage of the transistor may be controlled by adjusting the work functions.
When a metal film (metal gate electrode) is formed as a conductive thin film with the miniaturization or complication of device shapes, a method of forming a film using a plurality of material gases has been adopted. With the miniaturization of devices, the width of a space in which the metal film may be deposited is reduced, so that a layer thickness of a gate electrode used to adjust a work function can tend to be reduced. Presently, a metal-containing film which is a metal nitride film [for example, a titanium nitride (TiN) film] has widely been adopted as a metal gate electrode (Patent Document 1).